1. Technical Field
The present inventive concept relates to a nonvolatile memory device and a method for fabricating the same, and more particularly to a three-dimensional (3D) flash memory device and a method for fabricating the same.
2. Discussion of the Related Art
A semiconductor memory device is an electronic data storage device that may be implemented using a semiconductor such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), and indium phosphide (InP). The semiconductor memory device may be classified as a volatile memory device or a nonvolatile memory device.
The volatile memory device retains stored data as long as power supply is on, but when the power supply is off or interrupted the stored data is lost. The volatile memory device types may include static random access memory (SRAM), dynamic RAM (DRAM), and synchronous DRAM (SDRAM). The nonvolatile memory device can retain stored data even when not powered. The nonvolatile memory device types may include a flash memory device, a read only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), and a resistive memory (for example, a phase-change RAM (PRAM), a ferroelectric RAM (FRAM), and a resistive RAM (RRAM)).
To advance the degree of integration of a nonvolatile memory device, a three-dimensional memory device in which unit memory cells are vertically disposed has been developed.